Percy Jackson: Sea of Monsters is a good special effects family movie that’s every bit as accomplished as The Lightning Thief and possibly better—even if it doesn’t follow the Rick Riordan juvenile fantasy novels like a road map.

My teenage son has read every one of the Percy Jackson and the Olympians books, and as our family watched Percy Jackson: Sea of Monsters, the sequel to the 2010 fantasy-adventure Percy Jackson and the Lightning Thief, he couldn’t contain himself. He offered a running commentary:

“It’s like they compressed the next three books into one movie.”
“None of this was in the books.”
“This WAS in the books, and it’s actually handled pretty well.”
“I like the way the manticore moves. It’s really realistic.”
“The CGI in this movie is much better than the first one.”

And so on.

His final assessment surprised me, partly because he had seen the trailer and pronounced it “dumb,” and partly because many fans of the books had pretty much washed their hands of the movies because of how much they strayed from the texts. But my son decided it was “better than the first one, with better special effects.” Even though it wasn’t exactly faithful to the books, he felt it was “still good.” If he had give it a grade, he said he’d award it a B+ or A-, because it was action-packed, the CGI effects were great, and the pacing was good. My pre-teen daughter agreed, even though she hadn’t read the books. So did my wife.

So who needs a movie critic? I came to the same conclusions, though I did find fault with some of the CGI effects. For me, the visual shortcomings were the forehead and eye design of Percy’s half-brother, the cyclops Tyson (Douglas Smith)—which looked smeared with Vaseline in medium shots—and Percy (Logan Lerman) and his friends’ descent into the toothy vortex of a sea monster, which also was less than realistic. Everything else—and that includes some pretty fantastic creatures and water effects—looks convincing, and in truth it’s the visual effects that propel the film.

Good thing, because the plot can get a little confusing. In fairness, the same, I’m told, could be said about The Sea of Monsters, the book this film is mostly based upon. The film-version Percy, you may know, is older than the 13-year-old hero of Riordan’s books, but here, as in the book, the half-mortal son of Poseidon is saved by a half-brother he never knew existed until now. At Camp Half-Blood, the only safe haven for Percy and other demigods, the tree that sprung from one of their own—Thalia’s sacrifice—becomes poisoned, and the camp’s protective barrier is compromised. To save her and all the demigods from outside forces that want to kill them, Percy and friends Annabeth (Alexandara Daddario), Grover (Brandon T. Jackson), Tyson, and a rival named Clarisse (Leven Rambin) search for the Golden Fleece of old, which has the power to heal and restore. Also, as in the book, the evil demigod Luke (Jake Abel) is after the same prize, but for selfish (i.e., megalomaniacal) reasons.

If you’re looking for an absolutely faithful book-to-screen transformation, you won’t find it here. In this film version, the Titan god Kronos is plucked from future volumes and plays a major role in the unfolding mayhem. There are other major differences, but I won’t play the spoiler game. A chaotic plot is bolstered by frenetic action and visual effects, and that makes all the difference in this strange part-Olympian world—just as a surprising veneer of humor gives it all a tongue-in-cheek quality that’s lacking in other fantasy series.

Percy Jackson: Sea of Monsters is rated PG for “fantasy action violence, some scary images and mild language, and it has a runtime of 106 minutes.

Harry Potter remains the high-water mark for young adult books turned into fantasy films, but that series became problematic for some families because it began with a PG rating and gradually grew darker and more violent and traumatizing, making it an awkward choice for families with younger children. The Percy Jackson series continues to appeal to a broad audience with its PG rating, violence blunted by humor, and a growing sense that even people who die might not necessarily be dead. After all, these folks are part immortal, aren’t they? And what better way to introduce young fans to a fantasy world that can be, more often than not, as brutal as the real world.